1. Field of the Invention
This invention relates to carriers for pin grid array devices, and more specifically, to one and two-part carriers which provide extraordinary simplification, reduced cost, and other advantages in procedures for handling pin grid array devices supported on carriers.
2. Prior Art
A pin grid array is an integrated circuit device generally having a flat and square-shaped body with an array of electrical terminal pins projecting from a face of the body. A common pin grid array configuration comprises a square-shaped body with two or more parallel rows of pins extending around the perimeter of the body to form a grid pattern, with an integrated circuit chip in a central region of the body inside the pin grid pattern at the perimeter. Other pin grid array configurations also can be used.
A pin grid array is commonly manufactured in a wide variety of body sizes, which can vary from approximately 1.060 inch square to approximately 1.600 inch square, or larger, for example. The number of pins on a pin grid array also can vary, from nine pins per side to fifteen pins per side, or more, for example.
Pin grid arrays are commonly placed in individual carriers to protect them during subsequent handling steps. While placed in such carriers, the pin grid arrays can be marked and tested, for example. One carrier for a pin grid array comprises a base with an opening in its center and an array of holes around the central opening in a grid pattern to receive the pins of the pin grid array. The body of the pin grid array is mounted in a square-shaped recess on the opposite side of the carrier base, while the integrated circuit (chip) is retained in the central opening of the carrier. Flexible retaining clips adjacent the rectangular recess clip onto opposite sides of the body for holding it in place on the carrier base. The clips can be spread apart by mechanical means when removing the pin grid array from the carrier.
This type of carrier requires a different carrier design for each different pin grid array device. Inasmuch as pin grid arrays are available in different body sizes, the retaining mechanism in each carrier must be arranged to connect to a pin grid array body of a specific size, while the hole pattern in the carrier must match the array of pins on each different pin grid array. Tooling or machinery used to open the carrier also must vary for each different sized pin grid array. The opening mechanism must engage the retaining clips at their correct locations on each different type of carrier device to remove its particular sized pin grid array.
The present invention provides one and two-part pin grid array carriers which avoid the disadvantages of the conventional pin grid array carriers. The carriers of this invention greatly reduce production costs for constructing pin grid array carriers capable of carrying pin grid arrays of various size. In addition, the carriers of the present invention permit pin grid arrays to be removed from the carrier independently of the size of the pin grid array body so that a common opening mechanism can be used for all pin grid array sizes. In addition, the pin grid array can be removed along with one part of the two-part carrier. This removable part protects the pin grid array during subsequent testing and other handling steps while not interfering with such testing as is commonly the case with the conventional carriers. The carriers of this invention have further advantages when compared with the conventional pin grid array carriers, and these further advantages are described below.